Spatial Taming and Trapping of Molecules

达德利赫施巴赫是由实验物理化学计划的支持，以开发一种装置，操纵和捕获分子具有非常低的平移能量。 这将通过分子束膨胀冷却从高速对转转子的周边离开的气体来实现，使得转子尖端运动抵消膨胀速度。 也可以选择通过共同旋转转子来将速度增加到热速度以上。 基本的生存能力是建立使用CO2和技术正在开发和扩展到其他气体（O2，Cl 2，HCl和CO）。 正在进行的五项发展是：1）改进转子结构并消除设计弱点; 2）增加超音速膨胀的压力以实现较低的温度; 3）改善真空以减少慢分子散射; 4）开发收集慢分子的技术和5）使用脉冲气体喷嘴以改善超音速束的单向性。 与这些发展并行的是a）低温化学研究，特别是OH的研究，B）使用不均匀的静电场和激光场来散射或聚焦慢粒子，以及c）通过分子衍射来证明慢粒子的德布罗意布罗意性质。这些研究正在开发一种装置，其中分子可以冷却到非常低的温度，温度低至绝对零度以上一度。 在这些温度下，分子的速度为每秒几十米，波长与它们的大小相比很大。 这完全改变了分子之间反应碰撞的性质，开辟了化学行为的新领域。 该装置使得分子的速度可以连续增加，从而能够确定能量对过程的影响，并观察到向常规行为的转变。

Dudley Herschbach is supported by the Experimental Physical Chemistry Program to develop an apparatus for manipulating and trapping molecules with very low translational energies. This will be accomplished by molecular beam expansion cooling of gases exiting from the periphery of a high speed contra-rotating rotor such that the rotortip motion cancels out the expansion velocity. There is also the option of increasing the velocity above thermal by co-rotating the rotor. The basic viability was established using Xe and the technique is being developed and extends to other gases (O2, Cl2, HCl and CO). Five developments being made are to: 1) improve the rotor construction and eliminate design weaknesses; 2) increase the pressure for the supersonic expansion to achieve lower temperatures; 3) improve the vacuum to reduce slow molecule scattering; 4) develop techniques for collecting the slow molecules and 5) use a pulsed gas nozzle to improve the uni-directional nature of the supersonic beam. In parallel with these developments, there are a) studies of chemistry at low temperatures, specifically that of OH, b) use of inhomogeneous static and laser fields to scatter or focus the slow particles and c) demonstrations of the de Broglie nature of the slow particles by molecular diffraction.The studies are developing a device in which molecules can be cooled down to very low temperatures, as low as one degree above absolute zero of temperature. At these temperatures, the molecules have speeds of a few tens of meters per second and have wavelengths large compared with their size. This entirely changes the nature of the reactive collisions between molecules, opening up a new realm of chemical behavior. The device is such that the speed of the molecules can be increased continuously, enabling the effect of energy on the process to be determined and the change-over to conventional behavior to be observed.